1. Field of the Invention
The invention relates to surface heating and a heatable object using it, as well as, a method for production of surface heating. According to another aspect of the present invention, it relates to seat occupancy recognition, a seat using it, as well as, a seat occupancy recognition method, as individual configurations, as well as, in combination with the surface heating, the method for its production and the heatable object.
In particular, the present invention relates to seat heating, a heated seat, as well as, a method for its production. The invention also preferably relates to heating for side panels and floor coverings, especially in vehicles, side panels and floor coverings equipped with it, especially in vehicles, as well as a method for their production. The present invention also relates to, in particular, mattress heating, a heated mattress, as well as, a method for its production.
2. Prior Art
Seat-heating is known for vehicles from practice, which represents surface heating and is formed by current-carrying metal conductors as heating wires, which are arranged between cushion layers. This requires not only a demanding design of a correspondingly equipped seat, but has drawbacks, especially during operation. Because of the stronger heating of surrounding layers in the immediate vicinity of the heating wires, there is the risk of overheating, which can lead to damage of the cushion layers and/or the heating wires, and even cause a fire. In addition, the heat distribution is not optimal over the surface, since the temperature is always higher in the region of the heating wires than at a distance from them. Another drawback of this known design is the mechanical load to which the heating wires are subject when an occupant uses the seat, since the conductor wires may thereby break, which can lead to loss of function and/or result in an additional source of fire.
From DT 26 16 771 A1, a composite heating panel, made of a plastic laminate, with an incorporated semiconducting layer is known, which provides directed radiant heat. This laminate consists of a rigid plastic laminated structure, which is formed from at least one layer of a reinforced substrate basic material and a resin coating on this material, a semiconductive carbonaceous pyropolymer, which is bound to a heat-resistant, inorganic oxide support of large surface area, which is incorporated on at least one side of at least one layer of the substrate material, a heat-reflecting layer, incorporated in a position on one side of the pyropolymer on the substrate material, and power supply devices to parts of the layer made of conductive, carbonaceous pyropolymer, and which produces electrical resistance heating in the laminate, which is reflected and radiated by the heat-reflecting layer of the composite element. Such heating panels will be used as part of a wall of a living room or an office.
In this state of the art, the incorporation of the semiconducting layer into the laminate can take place in that finely comminuted carbonaceous pyropolymer, in the form of small particles or as powder, is mixed with a suitable support or vehicle in such a way that it is applied, spread or otherwise brought to the surface of a resin-coated glass cloth, paper, felt, cardboard, etc., as the laminated substrate or on a wood veneer, which is used in the laminated panel. The finely comminuted carbonaceous pyropolymer can also be mixed with the resin or polymer material, with which a specially reinforcing base material is to be impregnated or which is to be applied on this base material as a coating, wherein this base material is applied in or on the substrate by immersion or coating, and the resulting coated substrate is subjected to a semi-hardening of the type that the semiconductive pyropolymer leads to a uniform impregnation and coating via the resulting semicured, laminated sheet.
DE 33 16 182 A1 discusses the use of molded articles, such as films, plates, or spatially molded structures, from the class of the pyrrole polymers, which are complexed with anions, as electrical heating elements, in particular, for the heating of corrosive liquids or gases. The molded articles can also be coated with organic plastics.
A polymeric composite heating element is described in DE 35 24 631 A1 and has the form of a film, tube, or rod. Such polymeric composite heating elements can be used as such as heating sources, or can be laminated with conventional plastic films in order to improve the material strength.
The use and production of electrically conductive thermoplastic polyurethanes are known from DE 33 21 516 A1. Corresponding products are suitable for, among other things, the production of 1- to 2-mm-thick films for surface heating elements.
Thus, heating devices with electrically conductive plastic are rudimentarily known, but the entire state of the art does not contain any data or suggestion concerning how such heating devices are to be equipped and produced so that they can be used in actual practice.
In a number of other publications of International Patent Class H05B 3/36 and 3/84, surface heating is explained on the basis of examples of external mirrors for vehicles, which contain a layer of electrically conductive plastic. Three films of electrically conducting plastic are used on essentially rigid supports. Use of a film of electrically conducting plastics on the support structure of the vehicle seat is not possible, however, since the entire overlying cushion layers, etc., must then be heated in order for the heat to reach a seated occupant, which would be a considerable waste of energy.
No usable surface heating with electrically conducting plastics is known, especially for seat or couch substrates. For vehicle seats or mattresses, e.g., however, simple, cost-effective and operationally reliable heaters would be desirable.